stack

Overview

prototype::stack<T, Container> is a LIFO (Last-In, First-Out) container adaptor. It wraps an underlying container (default: deque) and exposes only stack operations.

When to Use

• Expression evaluation, undo systems
• DFS traversal without recursion
• Any LIFO access pattern

API Reference

namespace prototype {

template <typename T, typename Container = deque<T>>
class stack {
public:
    stack();

    T& top();
    const T& top() const;
    bool empty() const;
    size_t size() const;
    void push(const T& value);
    void push(T&& value);
    void pop();
    void swap(stack& other);
};

} // namespace prototype

Example Code

#include <prototype/containers/stack.hpp>

prototype::stack<int> undo_stack;
undo_stack.push(save_state());
// ... do work ...
int prev = undo_stack.top();
undo_stack.pop();
restore_state(prev);

Performance Characteristics

Operation	Complexity	Notes
push	O(1) amortized	Delegates to underlying container
pop	O(1)
top	O(1)

Design Notes

• Thin adaptor all performance depends on the underlying container
• Use stack<T, vector<T>> for contiguous storage
• Use stack<T, fixed_vector<T, N>> for zero-allocation stack